I was a bit in your place not to long ago. While everything else was great in our relationship my now fiancee and I had sex issues. When I wanted to talk about it she changed the subject, and so little was ever resolved. I had always made the mistake of telling her my problems with the way our sex life was without telling her that the reason it was so important to me was that it made me feel unwanted. I highly recomend theropy, and if not that then at least ask the minister who will preform the ceremony if there is any counciling sessions he will do and attend them as early as possible. If you come from a strong religious back ground sometimes that causes a dilema (this was our problem until the minister reminded her that sex between spouses is a COMPLETELY acceptable thing in the church's eyes and that as prospective spouses it was important to talk about it). Once she had the ok the talking began ad we are closer now.
I got engaged with issues still to work out as it sounds like you have done. There is a certain amount of just knowing its right. I can't explain what I love about her, its not a thing, or a group of them. I love her and it sounds like you feel the same about your Mrs. As Lilith said (she is always so damn smart) you probably already know the answer, if you can't see being without her then go for it, if you are only getting married because of what society says, or you've already spent so much time on it you may want to reconcider. The break up could get nasty but it would be worse 10 years from now.
Again I am not saying one way or the other only two people know that answer. Talk to the other one, tell her you wonder if your doing the right thing. Hell, anything that concerns you both you need to talk about, get ready now for treating the two of your lifes as one shared life.

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